Electric switch



(No Model.)

0. S. PLATT.

ELECTRIC SWITCH.

No. 427,522. Patented May 6, 1890.

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UNITED STATES PATENT OFFICE.

OCRCN S. PIIATT, OF BRIDGEPORT, CONNECTICUT.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 427,522, dated May 6, 1890. Application filed October S1, 1889. Serial No. 328,830. (No model.)

To all whom it may concern:

Be it known that I, OORON S. PLATT, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and State of Connecticut., have invented certain new and useful Improvements in Electric Switches; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain new and useful improvements in electric switches; but more particularly is it designed to apply to that class of switches known as double-pole switches, although switches of the single-pole type may be constructed to operate upon the same principle.

The object of my invention is to furnish a switch which shall be simple and economical to manufacture, in which both contacts shall be simultaneously actuated both in making and breaking the circuit by engagement or disengagement with the terminals, and in which the contact-arms'shall be, when in contact, firmly held as against accidental displacement; and with these ends in view my invention consists in the details of construction and combination of elements hereinafter fully explained, and then recited in the claims.

In order that those skilled in the art to which my invention appertains may fully understand how to make and use my improvement, I will describe the same in detail, reference being had to the accompanying drawings, which form a part of this specification, and in which- Figure l is a sectional elevation of the switch in its closed position; Fig. 2, a similar View open; Fig. 3, a plan view, partly in section, and showing the switch closed; Fig. 4, a detail elevation showing a slightly-modiied construction, the contacts in their open position; Fig. 5, a similar view, the contacts in closed position; Fig. 6, a detail sectional end View of one of the contacts; Fig. 7, a detail bottom plan view of one of the contact-arms, and Fig. 8 a transverse section on line x of Fig. 7.

Like numerals refer to the same parts in all the ligures.

I is the base-block, upon which, properly insulated from each other, are the terminals 2. In the center of this block is a casting having thereon two pairs of upwardly-projecting lugs 3 and a housing 4 with a closed top.

5 are contact-arms pivoted between the lugs 3 and provided at their outer ends with suitable conducting element-s for making contact with the terminals-such, for instance, as the flexible plates 6. (Shown at Fig. 6.) The inner ends of the con tact-armsare preferably rounded, as seen at Figs. 2 and 3, and each has in its under surface a notch 7, V-shaped in cross-section, as appears at detail, Figs. 7

and 8. In order to economize space, I preferably concave the ends of the arms, as seen at Fig. 7, so that in their closed position they may partially surround the spindle.

8 is a spindle having bearings, respectively, in the top of the housing and in a recess in the casting, which is mounted on the block. At its upper end this spindle is provided with a handle 9, whereby it may be freely turned about its axis, and just above its lower bearing a wedge-shapedcam 10, which appears in elevation in two positions at Figs. l and 2 and in plan view at Fig. 3. The ends of the contact-arms rest against this cam and, as hereinafter will appear, are actuated thereby.

ll is a washer arranged around the spindle above the cam, saidwasher adapted to rest upon the inner ends of the arms, and 12 is a spring coiled about the spindle and bearing against the top of the washer and the inner surface of the housing. In the opposite sides of the cam, near the bottom end thereof, are notches 18, into either of which the point of a spring 14 is adapted to take.

. In the operation of my invention, when the .switch is open the inner ends of the contactarms rest against the inclined surfaces of the cam at either side the ridge of the latter, (see Fig. 2, whereby the contacting elements are raised clear of the terminals. The downward pressure of the spring on the washer serves to keep them in this position. When it is desired to close the circuit, the spindle is rotated by means of the handle and the cam turned ninety degrees. rlhis brings the ridgeline of the caln into line with the length' of the contact-arms, which meanwhile are turned upon their pivotal points by their inner ends IOO riding up on the inclined surfaces of the cam. When this movement is completed, the contacts have passed into engagement with the terminals and the sharp upper edges of the cam take into the notches in the lower surfaces of the contact-arms, (see dotted lines, Fig. 1,) and thereby prevent any accidental disengagement. This engagement is not, however, such as to prevent the ready rotation of the cam by the spindle and handle when it is desired to break contact, and when such rotation is effected so far las to carry the inclined surfaces of the cam into contact with the ends of the arms the downward pressure of the spring will continue to rotate the cam until the parts are in the position shown at Fig. 2.

In order that the notches in the bars may be as shallow as possible, I may employ as adj unctive thereto the spring and notches heretofore described; but these are not essential, as under ordinary circumstances the engagement of the cam-ridge and notches is sufficient for all practical purposes.

In the switch herein described the handle may be turned `in either direction and still a change in the position of the switch effected. Furthermore, the closing and opening movements, and particularly the latter, are rapid, as is demanded in a practically-effective instrument.

l. In an electric switch, the combination, with the terminals, of a pair of independent contact-arms.pivoted midway of their length,

a central rotatable spindle arranged between the inner ends of said arms, a wedge-shaped cam carried by said spindle and engaging the ends of said arms from beneath, and a spring surrounding said spindle and adapted-to actuate the inner ends of the contact-arms downward, substantially as set forth.

2. In an electric switch, the combination, with the terminals, of a pair of independent and pivoted contact-arms, a central rotatable spindle having a wedge-shaped cam interposed between the inner ends of the contactarms, a washer loose on the spindle and bearing from above on the ends of the contactarms, and a spring bearing upon the upper surface of the washer, substantially'as set forth.

3. In a switch of the character described, the combination, with the terminals, of the central casting having the lugs, the housing, the spindle extending vertically through the housing and having an end bearing in the casting, the contact-arms pivoted between the lugs and having notched inner ends, the cam having a sharp central ridge secured upon the spindle, the washer loose upon said spindle, and the spring arranged around the spindle and interposed between the top of the housing and the washer, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

OCRON S. PLATT.

Vitnesses:

S. Il. HUBBARD, M. C. HrNonoLrFrE. 

